Pb-Sr-Nd isotopes

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Gutenberg Open Science: Application of Sr-Nd-Pb isotopes to the late quaternary paleoceanography of the Atlantic Ocean

Gutenberg Open Science: Application of Sr-Nd-Pb isotopes to the late quaternary paleoceanography of the Atlantic Ocean

Mineral dust deposited in the Northeastern Tropical Atlantic Ocean over time provides an important archive of sources of dust and paleoclimate prevailing in the Sahara and Sahel regions of North Africa. Radiogenic isotopes are arguably the most definitive means of characterizing dust emission sources from this region, but only a single sedimentary record exists of how dust sources evolved through time. Here, we have undertaken a Pb, Nd and Sr isotope study on the detrital fraction of sediment core GeoB2910-1 (4°50'N, 21°03'W, 2,703 m) located on the Sierra Leone Rise (SLR), which consists solely of eolian dust transported westwards from the African continent. Our 180-kyr record improves our understanding of the provenance and mixture of dust from potential source areas (PSA) on the adjacent African continent and transport pathways to the Sierra Leone Rise; variations in the record are driven by climate (aridity/humidity) and the prevailing wind regimes over West Africa. Our study shows that two principle source end-members in the Sahara-Sahel region are contributing to GeoB2910-1 in about equal proportions, and are located in the Bodélé Depression (PSA-5) and Northern Mali/Southern Algeria (PSA-3). Dust is delivered to the SLR mainly during the boreal winter, based upon published models, associated with a southward shift of the intertropical convergence zone (ITCZ); the ITCZ migrates northward during the summer monsoon months and blocks dust transport. The radiogenic isotope compositions do not vary significantly over glacial-interglacial cycles, indicating that emission sources remained relatively stable in this region, despite greatly enhanced dust loading in the atmosphere globally during glacial periods.
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Fluid/rock interaction and mass transfer in continental subduction zones: constraints from trace elements and isotopes (Li, B, O, Sr, Nd, Pb) in UHP rocks from the Chinese Continental Scientific Drilling Program, Sulu, East China

Fluid/rock interaction and mass transfer in continental subduction zones: constraints from trace elements and isotopes (Li, B, O, Sr, Nd, Pb) in UHP rocks from the Chinese Continental Scientific Drilling Program, Sulu, East China

Peacock 1990 ). Since subducted oceanic material rarely returns back to the surface, inferences about the fluid inventory during subduction relies on indirect evidence, such as the analysis of arc rocks. In contrast, deeply sub- ducted continental crust is usually brought back to the surface due to its lower density. However, only limited attention has been paid so far to the role of fluids during subduction and exhumation of continental crust (e.g., Zheng 2009 ). In comparison with hydrated oceanic crust, subducted continental crust is drier, commonly older and colder, less dense, and enriched in incompatible elements. Nevertheless, subducted continental materials must have been subjected to dehydration, releasing fluids from the subducting slab. Substantial amounts of H 2 O may have been transported to depths of more than 100–200 km by hydrous minerals during UHP metamorphism (Poli and Schmidt 1995 ; Thompson 1992 ). Volatiles released by decomposition of hydrous phases may enter the structure of anhydrous mantle minerals (Su et al. 2004 ; Xia et al. 2005 ). Lithium (Li), boron (B) and oxygen (O) isotopes are excellent tracers for fluid/rock interactions during down- going and uplift processes of subducted slabs (e. g., Elliott et al. 2006 ; Ionov and Seitz 2009 ; Leeman et al. 2004 ; Magna et al. 2006 ; Moriguti and Nakamura 1998 ; Moriguti et al. 2004 ; Teng et al. 2007 ; Tomascak 2004 ). Early Li and B isotope analyses have highlighted the behavior of these elements under hydrothermal and low-temperature condi- tions, with the heavier isotopes ( 7 Li and 11 B) becoming enriched in fluid phases (Chan et al. 1992 ; Hervig et al.
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Nd–Sr–Hf–O isotope provinciality in the northernmost Arabian–Nubian Shield: implications for crustal evolution

Nd–Sr–Hf–O isotope provinciality in the northernmost Arabian–Nubian Shield: implications for crustal evolution

Single zircon grains from rocks of the CA2 and AL suites were analyzed for Lu–Hf isotopic composition by MC- ICP-MS at the Ecole Normale Supe´rieure de Lyon. Hf isotope analysis followed careful characterization of the grains using CL images, ion-microprobe U–Pb dating and d 18 O analyses of the same domains as dated by U–Pb (Be’eri-Shlevin et al. 2009a ). The main target was rep- resentative, homogenous grains in terms of age and d 18 O. Representative zircons were hand-picked out of the epoxy ion-microprobe mounts, examined under an optical microscope to ensure the removal of most epoxy, and leached in consecutive batches of cold concentrated nitric and hydrofluoric acids. Dissolution and analytical proce- dures follow Blichert-Toft and Albare`de ( 2008 ) except that Pb isotopes were not measured. Age corrections due to the radiogenic ingrowth of 176 Hf since zircon crystal- lization (*770–580 Ma) vary from 8 to 96 ppm. eHf(T) was calculated using present-day values for
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Edoweb: ND-ALBUM Kahlheckerhofflur

Edoweb: ND-ALBUM Kahlheckerhofflur

ND-Album „Kahlheckerhofflur“ - 5 - Luftbild des GLB Kahlheckerhofflur. In der Bildmitte die gepflegte Pulsatillenflur mit einzelnen Obstbäumen, oben anschließend ein Wäldchen mit altem Baumbestand. (LANIS, 2018)

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Xi-Produktion in Pb+Pb Stößen bei 40 A GeV am CERN SPS

Xi-Produktion in Pb+Pb Stößen bei 40 A GeV am CERN SPS

Der NA49-Detektor ist in der Lage, Teilchen in einem weiten Rapiditätsbereich zu messen. In Abbilung 2 (rechts) wird die Rapiditätsverteilung der Ξ − in zentralen Pb+Pb-Kollisionen bei einer Energie von 40 A GeV gezeigt. Das Spektrum kann gut mit einer Gaussfunktion beschrieben werden, wie die durchgezogene Linie zeigt. Aus der Integration dieses Spektrums lässt sich die totale Anzahl der Ξ − im gesamten Phasenraum zu (2.41 ± 0.15 ± 0.24) Ξ − s pro Kollision bestimmen [4].

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Heavy Isotopes of Protactinium 

Heavy Isotopes of Protactinium 

The nuclides 9.1-min 237Pa, 9.1-min 236Pa and 24-min 235Pa, produced by irradiations of uranium isotopes with 14-MeV neutrons and 100-MeV bremsstrahlung, were also studied since only [r]

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Edoweb: ND-Album Bergwiese

Edoweb: ND-Album Bergwiese

ND-Album „Bergwiese“ - 7 - Biotoptypische und seltene Arten Pflanzenarten: • Sumpf-Scharfgabe (Achillea ptarmica) • Echter Ziest (Betonica officinalis) • Blaugrüne Segge (Carex flacca) • Behaarte Segge (Carex hirta)

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Edoweb: ND-Album In den Almen

Edoweb: ND-Album In den Almen

Die kleinflächigen Trockenrasen zwischen Leistadt und Kallstadt sind eine regionale Besonderheit, die durch anstehende Kalkfelsen entstehen konnte. Es ist Teil des FFH- Gebietes „[r]

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Edoweb: ND-Album Auf dem Galgenberg

Edoweb: ND-Album Auf dem Galgenberg

- 6 - ND-Album „Auf dem Galgenberg“ Insbesondere das Silber- gras braucht klein- flächige Bodenverwun- dungen, da es als Pionierpflanze offene vegetationsarme Stellen braucht, um sich über Samen und Ausläufer zu behaupten.

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Edoweb: ND-Album Auf dem Bordsberg

Edoweb: ND-Album Auf dem Bordsberg

ND-Album „Auf dem Bordsberg“ - 11 - Biotoptypische und seltene Arten Pflanzenarten:  Arznei-Thymian (Thymus pulegioides agg.)  Astlose Graslilie (Anthericum liliago)  Aufrechte Trespe (Bromus erectus)  Aufrechter Ziest (Stachys recta)

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J/ψ production in √sNN = 5.02 TeV Pb−Pb collisions

J/ψ production in √sNN = 5.02 TeV Pb−Pb collisions

4 Measurement of J/ψ in PbPb collisions with ALICE event. The so-called physics selection identifies, in a first offline selection step, events contaminated by pileup or of low reconstruction quality and removes them from the event sample. For the given data sample, the physics selection applies an offline reevaluation of the information from the V0 detectors. This reevaluation is based on a detailed analysis of the raw data from the V0 detectors. The criteria for the signal amplitudes and the time correlation of the signals of the V0-A and V0-C signals are revisited and adjusted in comparison to the online trigger configuration. If the three ZDC subdetectors are available, a rejection of pileup events, based on the relative time information of them, is applied. To reject events with a bad qual- ity in terms of the TPC data reconstruction quality, the actual high voltage of the readout chambers is compared with the nominal values.
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Edoweb: ND-ALBUM Hungerpfuhl

Edoweb: ND-ALBUM Hungerpfuhl

Zustand (früher): k. Bisher erreichtes Ziel: Offenhaltung des Teiches und der Gewässerrandbereiche und damit Erhalt standorttypischer Tier- und Pflanzenarten.. Stanula, April 2018).[r]

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Pressure‐induced Pb–Pb bonding and phase transition in Pb2SnO4

Pressure‐induced Pb–Pb bonding and phase transition in Pb2SnO4

We cross-checked our experimental results with those of DFT-based calculations in both possible space groups for Pb 2 SnO 4 (Tab. 1). Our DFT-based calculations reproduce the experimental diffraction data satisfactorily with an over- estimation of the unit-cell lengths by <3% due to the well established ‘underbinding’ in DFT-GGA-PBE calculations. The DFT calculations carried out here provide structural and physical parameters in the athermal limit. As has been discussed in the introduction, structurally closely related Pb 2 PbO 4 undergoes a tetragonal $ orthorhombic phase transition at 170 K, so it is actually problematic to neglect temperature in DFT studies of this system. The DFT-based calculations gave the same total energy within the numerical accuracy for the orthorhombic and the tetragonal structure.
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Hyperon production in Pb+Pb collisions at the CERN-SPS

Hyperon production in Pb+Pb collisions at the CERN-SPS

Figure 2. Rapidity spectra of  (triangles),  − (circles) and  (squares) produced in central Pb+Pb collisions at 30, 40, 80 and 158 A GeV. Filled symbols are measured, and open ones are reflected at mid-rapidity. For clarity the -spectra are scaled by a factor 5 and the -spectra by a factor 20. The -spectra are uncorrected for feeddown from  and . All spectra are preliminary except  − at 158 A GeV.

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Relativistic many-electron SCF correlation diagram for Pb-Pb

Relativistic many-electron SCF correlation diagram for Pb-Pb

1s 96 electrons Pb ... 1 Se1f-consistent-charge relativistic Dirac-Fock corre1ation diagram for Pb on Pb with 96 e1ectrons. The levels are c1assified on the 1eft according to the Z-unite[r]

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Two-proton correlations from 158 AGeV Pb+Pb central collisions

Two-proton correlations from 158 AGeV Pb+Pb central collisions

In summary, NA49 has measured the two-proton cor- relation function at midrapidity from Pb+Pb central col- lisions at 158 AGeV. The peak height of the two-proton correlation function is 1.24 ±0.07 after corrections. From comparison between the data and the calculations for static thermal Gaussian sources, we extract an effective proton source size σ eff = 3.85±0.15(stat.) +0.60 −0.25 (syst.) fm. Within the error, the rqmd model (σ eff = 4.41 fm) and the venus model (σ eff = 3.55 fm) are consistent with the data. Due to the space-time-momentum correlation, the two-proton correlation function is sensitive only to a limited region of the proton source. Our measurement to- gether with the measurements at lower energies suggest a very weak dependence of the two-proton correlation function on bombarding energy. The observed structure at q inv ≈ 70 MeV/c is not understood.
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Anzeige von Eine einfache Übersetzungsregel für die nd-Formen

Anzeige von Eine einfache Übersetzungsregel für die nd-Formen

nd-Formen-Regel (...wird alles wieder leicht) Die mit der Gerundivkonstruktion verbundene Umkehrung des Abhängigkeitsverhältnisses muss dabei nicht unbedingt eingehend besprochen werden, da sie bei dem Weg über die wörtliche Hilfsübersetzung intuitiv von selbst klar wird: Statt ars carmina cantandi - „die Kunst des Lieder-Singens“ kann es auch ars carminum cantandorum heißen, „die Kunst der zu singen- den Lieder“ = „die Kunst des Lieder-Singens“. Die Bedeutung ist am Ende dieselbe, obwohl im ersten Fall carmina als Objekt von cantandi abhängt, im zweiten umgekehrt cantandorum als Attribut von carminum. Damit ist am Anfang die substantivische von der adjektivischen nd-Form unterschieden, was auch in den Benennungen Gerundium und Gerundivum zum Ausdruck kommt. Ab der Einführung der nd-Formen-Regel in der 4. Stunde spielt diese Unterscheidung zwar keine Rolle mehr und werden auch die Benen- nungen durch den gemeinsamen Überbegriff „nd-Formen“ ersetzt; doch schien mir das Risiko, dass bei Verzicht auf diese zumindest anfänglich klare Unterscheidung die beträchtliche syntakti- sche Differenz zwischen den Konstruktionen ars carmina cantandi und ars carminum cantandorum dauerhaft Verwirrung stiftet, immer zu groß.
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Edoweb: ND-Album Sandgrube Schulzendell

Edoweb: ND-Album Sandgrube Schulzendell

unterschiedliche Mikrostandorte.. Peerenboom 2008) Sandgrube Schulzendell, Gewässerfläche, direkt nach maschinellem Abräumen (K. Peerenboom 2009) Sandgrube Schulzendell, zwei Jahr[r]

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Edoweb: ND-Album Ruchheimer Wiese

Edoweb: ND-Album Ruchheimer Wiese

ND-Album „Ruchheimer Wiese“ - 5 - Blick nach Osten über den östlichen Wiesenteil mit Kleinem Mädesüß (Filipendula vulgaris, oben) und Ästiger Graslilie (Anthericum ramosum, unten) (Wiese: P.E. Jörns, 14.06.2010; oben: Albert H., Wikimedia Commons; unten: Albert H.,

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Edoweb: ND-Album Sandgrube am Etesrech

Edoweb: ND-Album Sandgrube am Etesrech

- 8 - ND-Album „Sandgrube am Etesrech“ Biotoptypische und seltene Arten Pflanzenarten (Auszug) • Schwimmendes Laichkraut (Potamogeton natans) • Lanzett-Froschlöffel (Alisma lanceolatum) • Schwarzfrüchtiger Zweizahn (Bidens frondosa) • Sumpf-Ruhrkraut (Gnaphalium uliginosum) • Kröten-Binse (Juncus bufonius)

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